Hole saw assembly including drive shafts supported by a rotatable annulus

Abstract

A hole-saw assembly including a hole-saw having at one end a plurality of cutting teeth and at the other end a base having two holes therethrough. two shafts. The assembly includes a mandrel coaxially aligned with said hole-saw and including a body having two bores therethrough, and an annulus located on top of the body which is coaxially aligned with said mandrel and hole saw. The annulus includes two shafts co-axial with the mandrel bores, and is rotatable around its longitudinal axis from a first to a second position. In the first position the annulus shafts are aligned with the base holes allowing the shafts to be freely insertable and removable and in the second position the shafts are misaligned to lock the shafts to the base. In one embodiment the mandrel bores are shaped to accommodate rotation of the shafts, and in a further embodiment, the shafts are configures to rotate within circular mandrel bores. Such an arrangement allows the hole-saw and the mandrel to be easily and quickly mountable and demountable.

The invention claimed is: 
     
       1. A hole saw assembly comprising:
 a hole saw adaptor having at one end a projected threaded portion and at the other end a face; 
 the face having at least one drive shoulder and further having at least one locking aperture; and 
 the adaptor further having a longitudinal bore therethrough; 
 a mandrel being engageable at one end with a drilling machine, at the other end having an arbor head, the arbor head having a drill bit projecting longitudinally from its center; 
 the arbor head further having at least one drive shaft extending longitudinally from said arbor head; 
 the arbor head further having at least one locking pin extending longitudinally from said arbor head; 
 wherein the locking pin is moveable from a first lock position to a second unlock position; and 
 wherein upon partial insertion of the adaptor onto the drill bit and into contact with the arbor head, the at least one drive shaft rotationally engages the drive shoulder of the adaptor and wherein upon further insertion of the adaptor onto said drill bit, the locking pin engages the at least one locking aperture relative to longitudinal movement between the arbor head and the mandrel. 
 
     
     
       2. The hole saw assembly as in  claim 1  wherein the at least one locking pin is biased in the lock position. 
     
     
       3. The hole saw assembly as in  claim 1  wherein said at least one locking pin is biased into the first lock position; and wherein movement of the adaptor onto the drill bit causes rotational movement of the at least one locking pin from the first lock position to the second unlock position; and when the at least one locking pin passes into the adaptor, the at least one locking pin moves back to the first lock position. 
     
     
       4. The hole saw assembly as in  claim 1  wherein the arbor head has two driveshafts. 
     
     
       5. The hole saw assembly as in  claim 1  wherein the arbor head has two locking pins. 
     
     
       6. The hole saw assembly as in  claim 1  wherein the adaptor has two drive shoulders. 
     
     
       7. The hole saw assembly as in  claim 1  wherein the adaptor has two locking apertures.